So I did my first chimney cleaning after burning for 3+ months last year and about a month this year. Here is what I have and what I discovered. There is 23 feet of stainless steel chimney on the outside of the house and about 3 feet of double walled pipe from the stove to the chimney. When I took off the bottom and shined a flashlight up the chimney I thought "oh no" as I saw black shiny material the entire length of the chimney. I did a bottom up cleaning from the outside through the plug using a 6 inch poly brush and the flexible rods and then took off the inside double wall pipe and cleaned it in the yard. I wish I would've put some newspaper down to catch the material but i didn't think about it. After running the brush up and down the chimney twice I looked at what came out and want some opinions. I probably had enough to fill a 12 ounce cup (maybe less) so not anywhere near came out what looked like was in the chimney. What I did have was small and granular but definitely black and shiny when hit with the flashlight. In the double wall pipe from the stove to the chimney was black powder so that looked ok to me. Last year the wood burned was seasoned between 2 and 3 years. This year the wood burned was about a year seasoned up to this point. The chimney didn't have much material left inside it at the end. Opinions.